Natural Convection Heat Transfer of Suspension

悬浮液自然对流传热

• 批准号: 14350111
• 负责人: OKADA Masashi
• 金额: $ 4.35万
• 依托单位: AOYAMA GAKUIN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350111/
• 关键词: Natural convection; Heat transfer; Suspension; Rectangular vessel; Sedimentation; Stratification; Particle Image Velocimetry; Depression of convection; 層崩壊

Natural convection heat transfer of suspension in a rectangular vessel was investigated. A vertical wall of the vessel was heated and the opposite vertical wall was cooled. SiO_2 fine particles with 3 or 6 μm of mean diameters were dispersed into water or Dimethyl Sulfoxide (DMSO) aqueous solution. The particle size distributions were narrow. The refractive index of the DMSO solution was matched to that of the SiO_2 particles and the velocity of the natural convection was measured with Particle Image Velocimetry. By using the water-SiO_2 suspension, the temperature and particle concentration distributions in the suspension and the average heat transfer coefficient on the vertical wall were measured under various conditions of the temperature difference, the initial particle concentration, the mean diameter of particle, and the width of the vessel. The mean Nusselt number of the natural convection of the suspension was compared with that of water. Sedimentation of particles affected the natural convection of suspension. When the initial particle concentration was large and the temperature difference was small, the natural convection was depressed and the Nusselt number became small. As the width of the vessel became wider, the Nusselt number decreased. When the initial particle concentration was small and the temperature difference was large, convection cells were stratified and the natural convection in the cells was active and the Nusselt number was more than 80% of that of water. If the number of the convection cells was two, the Nusselt number had the maximum when the position of the interface between the convection cells was near half of the vessel height.

研究了矩形容器内悬浮液的自然对流换热。加热容器的垂直壁，冷却相对的垂直壁。将平均粒径为3或6 μm的SiO_2微粒分散在水或二甲基亚砜（DMSO）水溶液中。粒径分布窄。用粒子图像测速仪（Particle Image Velocimetry）测量了DMSO溶液与SiO_2粒子的折射率匹配后的自然对流速度。采用水-SiO2悬浮液，在不同的温差、初始颗粒浓度、颗粒平均直径和容器宽度条件下，测量了悬浮液中的温度分布、颗粒浓度分布和竖直壁面上的平均传热系数。将悬浮液与水自然对流的平均努塞尔数进行了比较。颗粒的沉降影响悬浮液的自然对流。当初始颗粒浓度较大、温差较小时，自然对流受到抑制，努塞尔数变小。随着血管宽度的增加，Nusselt数减小。当颗粒初始浓度较小时，温差较大时，对流单体呈分层结构，单体内自然对流活跃，努塞尔数约为水的80%以上。当对流单体数为2时，当对流单体之间的界面位置接近容器高度的一半时，努塞尔数最大。

项目成果

Yoshikazu Teraoka, Masashi Okada, Shinji Nakagawa, et al.: "NATURAL CONVECTION OF SUSPENSION IN A RECTANGULAR VESSEL"The 1st International Symposium on Micro & Nano Te chnology. 1(CD-ROM). (2004)

Yoshikazu Teraoka、Masashi Okada、Shinji Nakakawa 等：“NATURAL CONVECTION OF SUSPENSION IN A RECTANGULAR VESSEL”第一届国际微观研讨会

Natural convection of suspension in a rectangular vessel

矩形容器中悬浮液的自然对流

• 发表时间: 2004
• 期刊: The 1st International Symposium on Micro & Nano Technology 1
• 作者: Yoshikazu Teraoka

PIVによる懸濁液の自然対流の可視化計測

使用 PIV 视觉测量悬浮液中的自然对流

• 发表时间: 2003
• 期刊: 第40回日本伝熱シンポジウム講演論文集 40-II
• 作者: 大野雄一朗

Natural convection heat transfer of suspension in a rectangular vessel

矩形容器中悬浮液的自然对流传热

• 发表时间: 2005
• 期刊: 42nd National Heat Transfer Symposium of Japan (in press)
• 作者: Yoshikazu TERAOKA;Masashi OKADA;Ryozo Shiroishi
• 通讯作者: Ryozo Shiroishi

大野雄一朗, 城石亮蔵, 岡田昌志, 中川慎二: "PIVによる懸濁液の自然対流の可視化計測"第40回日本伝熱シンポジウム講演論文集. 40-II. 467-468 (2003)

Yuichiro Ohno、Ryozo Shiroishi、Masashi Okada、Shinji Nakakawa：“使用 PIV 进行悬浮液中自然对流的视觉测量”第 40 届日本传热研讨会论文集 40-II 467-468。